[PATCH 15/15] perf record: Add --buildid-mmap option to enable mmap's build id

[Jiri Olsa]

Adding --buildid-mmap option to enable build id in mmap2 events.
It will only work if there's kernel support for that and it disables
build id cache (implies --no-buildid).

It's also possible to enable it permanently via config option
in ~.perfconfig file:

  [record]
  build-id=mmap

Also added build_id bit in the verbose output for perf_event_attr:

  # perf record --buildid-mmap -vv
  ...
  perf_event_attr:
    type                             1
    size                             120
    ...
    build_id                         1

Adding also missing text_poke bit.

Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 tools/perf/Documentation/perf-config.txt  |  3 ++-
 tools/perf/Documentation/perf-record.txt  |  3 +++
 tools/perf/builtin-record.c               | 20 ++++++++++++++++++++
 tools/perf/util/evsel.c                   | 10 ++++++----
 tools/perf/util/perf_api_probe.c          | 10 ++++++++++
 tools/perf/util/perf_api_probe.h          |  1 +
 tools/perf/util/perf_event_attr_fprintf.c |  2 ++
 tools/perf/util/record.h                  |  1 +
 8 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index e3672c5d801b..8a1c6c16821a 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -559,11 +559,12 @@ kmem.*::
 
 record.*::
 	record.build-id::
-		This option can be 'cache', 'no-cache' or 'skip'.
+		This option can be 'cache', 'no-cache', 'skip' or 'mmap'.
 		'cache' is to post-process data and save/update the binaries into
 		the build-id cache (in ~/.debug). This is the default.
 		But if this option is 'no-cache', it will not update the build-id cache.
 		'skip' skips post-processing and does not update the cache.
+		'mmap' skips post-processing and reads build-ids from MMAP events.
 
 	record.call-graph::
 		This is identical to 'call-graph.record-mode', except it is
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 768888b9326a..1bcf51e24979 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -482,6 +482,9 @@ Specify vmlinux path which has debuginfo.
 --buildid-all::
 Record build-id of all DSOs regardless whether it's actually hit or not.
 
+--buildid-mmap::
+Record build ids in mmap2 events, disables build id cache (implies --no-buildid).
+
 --aio[=n]::
 Use <n> control blocks in asynchronous (Posix AIO) trace writing mode (default: 1, max: 4).
 Asynchronous mode is supported only when linking Perf tool with libc library
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index d832c108a1ca..f6bfad096756 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -102,6 +102,7 @@ struct record {
 	bool			no_buildid_cache;
 	bool			no_buildid_cache_set;
 	bool			buildid_all;
+	bool			buildid_mmap;
 	bool			timestamp_filename;
 	bool			timestamp_boundary;
 	struct switch_output	switch_output;
@@ -2135,6 +2136,8 @@ static int perf_record_config(const char *var, const char *value, void *cb)
 			rec->no_buildid_cache = true;
 		else if (!strcmp(value, "skip"))
 			rec->no_buildid = true;
+		else if (!strcmp(value, "mmap"))
+			rec->buildid_mmap = true;
 		else
 			return -1;
 		return 0;
@@ -2550,6 +2553,8 @@ static struct option __record_options[] = {
 		   "file", "vmlinux pathname"),
 	OPT_BOOLEAN(0, "buildid-all", &record.buildid_all,
 		    "Record build-id of all DSOs regardless of hits"),
+	OPT_BOOLEAN(0, "buildid-mmap", &record.buildid_mmap,
+		    "Record build-id in map events"),
 	OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename,
 		    "append timestamp to output filename"),
 	OPT_BOOLEAN(0, "timestamp-boundary", &record.timestamp_boundary,
@@ -2653,6 +2658,21 @@ int cmd_record(int argc, const char **argv)
 
 	}
 
+	if (rec->buildid_mmap) {
+		if (!perf_can_record_build_id()) {
+			pr_err("Failed: no support to record build id in mmap events, update your kernel.\n");
+			err = -EINVAL;
+			goto out_opts;
+		}
+		pr_debug("Enabling build id in mmap2 events.\n");
+		/* Enable mmap build id synthesizing. */
+		symbol_conf.buildid_mmap2 = true;
+		/* Enable perf_event_attr::build_id bit. */
+		rec->opts.build_id = true;
+		/* Disable build id cache. */
+		rec->no_buildid = true;
+	}
+
 	if (rec->opts.kcore)
 		rec->data.is_dir = true;
 
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3dd0eae9810d..191500c1f9f6 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1168,10 +1168,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
 	if (opts->sample_weight)
 		evsel__set_sample_bit(evsel, WEIGHT);
 
-	attr->task  = track;
-	attr->mmap  = track;
-	attr->mmap2 = track && !perf_missing_features.mmap2;
-	attr->comm  = track;
+	attr->task     = track;
+	attr->mmap     = track;
+	attr->mmap2    = track && !perf_missing_features.mmap2;
+	attr->comm     = track;
+	attr->build_id = track && opts->build_id;
+
 	/*
 	 * ksymbol is tracked separately with text poke because it needs to be
 	 * system wide and enabled immediately.
diff --git a/tools/perf/util/perf_api_probe.c b/tools/perf/util/perf_api_probe.c
index 3840d02f0f7b..829af17a0867 100644
--- a/tools/perf/util/perf_api_probe.c
+++ b/tools/perf/util/perf_api_probe.c
@@ -98,6 +98,11 @@ static void perf_probe_text_poke(struct evsel *evsel)
 	evsel->core.attr.text_poke = 1;
 }
 
+static void perf_probe_build_id(struct evsel *evsel)
+{
+	evsel->core.attr.build_id = 1;
+}
+
 bool perf_can_sample_identifier(void)
 {
 	return perf_probe_api(perf_probe_sample_identifier);
@@ -172,3 +177,8 @@ bool perf_can_aux_sample(void)
 
 	return true;
 }
+
+bool perf_can_record_build_id(void)
+{
+	return perf_probe_api(perf_probe_build_id);
+}
diff --git a/tools/perf/util/perf_api_probe.h b/tools/perf/util/perf_api_probe.h
index d5506a983a94..f12ca55f509a 100644
--- a/tools/perf/util/perf_api_probe.h
+++ b/tools/perf/util/perf_api_probe.h
@@ -11,5 +11,6 @@ bool perf_can_record_cpu_wide(void);
 bool perf_can_record_switch_events(void);
 bool perf_can_record_text_poke_events(void);
 bool perf_can_sample_identifier(void);
+bool perf_can_record_build_id(void);
 
 #endif // __PERF_API_PROBE_H
diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
index e67a227c0ce7..656a7fddfc26 100644
--- a/tools/perf/util/perf_event_attr_fprintf.c
+++ b/tools/perf/util/perf_event_attr_fprintf.c
@@ -134,6 +134,8 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
 	PRINT_ATTRf(bpf_event, p_unsigned);
 	PRINT_ATTRf(aux_output, p_unsigned);
 	PRINT_ATTRf(cgroup, p_unsigned);
+	PRINT_ATTRf(text_poke, p_unsigned);
+	PRINT_ATTRf(build_id, p_unsigned);
 
 	PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
 	PRINT_ATTRf(bp_type, p_unsigned);
diff --git a/tools/perf/util/record.h b/tools/perf/util/record.h
index 266760ac9143..609e706f4282 100644
--- a/tools/perf/util/record.h
+++ b/tools/perf/util/record.h
@@ -49,6 +49,7 @@ struct record_opts {
 	bool	      no_bpf_event;
 	bool	      kcore;
 	bool	      text_poke;
+	bool	      build_id;
 	unsigned int  freq;
 	unsigned int  mmap_pages;
 	unsigned int  auxtrace_mmap_pages;
-- 
2.26.2